package com.itheima.reggie.Controller;

import com.itheima.reggie.exception.R;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@RequestMapping("/common")
@RestController
public class FileController {
    //file是一个临时文件，需要转存到指定位置,否则本次请求完成后临时文件会删除
    @Value("${reggie.path}")
    private String path;
    @PostMapping("/upload")

   // 文件的上传
    public R<String> upload(MultipartFile  file)
    {
        System.out.println("文件上传");
        //原文件的名字
        String name=file.getOriginalFilename();
       String suffx= name.substring(name.lastIndexOf("."));
//使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
        String fileName=UUID.randomUUID().toString()+suffx;
        //创建一个目录对象
        File dir=new File(path);
        //判断当前目录是否存在
        if(!dir.exists())
        {
            dir.mkdirs();
        }
        try {
            file.transferTo(new File(path+fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        return R.success(fileName);
    }
    //文件的下载

    @GetMapping("/download")
    public R<String> download(String name, HttpServletResponse response)
    {

        try {
            //输入流,通过输入流读取文件内容
            FileInputStream fileInputStream=new FileInputStream(new File(path+name));
            //输出流,通过输出流将文件写回浏览器,在浏览器展示图片
            ServletOutputStream outputStream=response.getOutputStream();
            int len=0;
            byte[] bytes=new byte[1024];
           while ((len=fileInputStream.read(bytes))!=-1)
           {
               outputStream.write(bytes);
               outputStream.flush();
           }
            fileInputStream.close();
            outputStream.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return R.success("下载成功");
    }

}
